A Case of Atypical Lipomatous Tumor of the Lower Leg

Abstract

Atypical lipomatous tumor (ALT) is synonymous with well-differentiated liposarcoma.Itusually occurs in the deep soft tissue of the extremities and in the retroperitoneum.A48-year-old woman presented with an ALT.Atumor arose in her lower leg several years prior to her visit.Thetumor was removed surgically and diagnosed as lipoma.Oneyear later, the tumor recurred at the same site.Weremoved it surgically.Histopathologically,the tumor was composed of various sizes of mature adipocytes and fibrous septa.It contained atypical stromal cells and lipoblast-like cells.Mature adipocytes were stained with MDM2 and CDK4.We diagnosed the lesion as ALT.No recurrence was detected nine months after the operation.The clinical behavior of ALT depends on the anatomical location of the tumor.Tumors occurring in the extremities or in the subcutaneous tissue have an excellent prognosis.